Method of and apparatus for electric welding



May 23, 1933. c. A. CADWELL METHOD OF AND APPARATUS FOR ELECTRIC WELDING Filed Jan. 9, 1930 5 Sheets-Sheet l INVENTOR. C/z arias C'ad'zue/i y 23, 1933- c. A. CADWELL 1,911,059

METHOD OF AND APPARATUS FOR ELECTRIC WELDING 's @WS A TTORNEYS May 23, 1933. c. A' CADWELL METHOD OF AND APPARATUS FOR ELECTRIC WELDING Filed Jan. 9, 1930 5 Sheets-Sheet 3 WW 4 A r M C A TTORNE :6.

y 1933- c. A. CADWELL 1,911,059

METHOD OF AND APPARATUS FOR ELECTRIC WELDING Filed Jan, 9, 1930 5 Sheets-Sheet 4 fl ca /5' I d 'los INVENTOR. O 0 (7147/66 f7. C'aclwcli A TTORNEYS.

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May 23, 1933. c. A. CADWELL 1,911,059

METHOD OF AND APPARATUS FOR ELECTRIC WELDING Filed Jan. 9, 1950 5 Sheets-Sheet 5 y INVENTOR. /0 C/lar/ea ZCadzUZ/Z A TTORNEYS Patented May 23, 1933 'ITED STATES PATET OFFHCE CHARLES A. CADWELL, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THE ELECTRIC RAILWAY IMPROVEMENT COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO METHOD OF AND APPARATUS FOR. ELECTRIC VJ'ELDING- Application filed January 9, 1930.

This invention, relating indicated to methods of and apparatus for electric welding, has specific reference to methods of and apparatus for electrically welding bonds to rails. The present improved method and apparatus constitute in certain respects an improvement on the method and apparatus disclosed in the patent to Kjellgren and Stephenson No. 1,309,9l7, dated July 15, 1919. Thus, one of the objects of the present invention is the provision of an apparatus whereby current of relatively high voltage may be utilized so that, for example, in welding rail bonds onto rails, current of the voltage regularly used in the operation of railways may be taken directly from the trolley through a minimum amount of resistance. Heretofore in operations of this sort it has been found necessary to utilize an electrode of high resistance material, bringing the same to the proper high temperature by passing therethrough a current of relatively low voltage and large amperage. By the present process, however, instead of relying upon the resistance of such an electrode I utilize the electric are which, as is well understood, will require a considerably higher voltage than that just indicated for such rcsistance electrode.

In employing the electric arc, however, in welding operations, particularly where the bodies are of unlike mass, and where, in addition, there may be a disparity in the temperatures of fusion, the smaller mass, for example, having both the lower temperature of fusion and the greater heat conductivity, an ordinary arc. as is well understood, cannot be successfully employed, as it will fuse or burn such small body long before the contact face of the larger body is brought to a welding temperature; or at least if the parts are welded together at all they are thus united only at a few points instead of uniformly throughout their contacting surface as is desirable, particularly in a rail bonding operation, where the object is to provide an adequate and at the same time permanent electrical connection across the joint between the two rails.

The method commonly employed to uti- Serial No. 419,662.

lize an electric arc to accomplish the proper homogeneous connection between the smaller body of relatively soft metal, such as the bond, with the larger body of relatively harder metal, such the rail, is carried out by pressing a heat-distributing plate against the exposed surface of the terminal portion of the bond and directing the electric are against this heat-distributing plate which brings about the proper distribution of the heat to effect a weld of high quality. Considerable difliculty has been experienced in the use of the electric arc in this manner since an electric arc is a relatively line thread of flame of a very high heat intensity. The placing of such an are against the heat distributing plate would result in a localized area in such plate becoming intensely heated and in many of the disadvantages resulting, which are the undesirable features of the use of the plain are. Some means must therefore be provided for spreading the are over the major portion of the heat distributing plate in order to effect a uniform heating of the element to be welded, against which the plate is pressed.

A common i'nethod of controlling an electric arc is to provide a solenoid coaXially with the electrode by means of which the arc is struck. The magnetic l nerof force as they diverge on leaving the end of the olectro-magnetic coil cause the arc to diffused over the major portion of the heat distributing plate. in order, however, for a solenoid to accomplish the above results such solenoid must be of cruisidcrable length in order to effect a proper control over the arc.

In welding bonds to rails the bond of necessity is secured either to the ball of the rail or to the ob thereof and in order to effect the heating of the heat-distributing plate as above described, the electrode, by means of which the arc is struck, must extend substantially at right angles to the length of the rail. If the solenoid or electron'lagnet c coil is to be mounted coaxially with the electrode such construction will, in a great many cases, cause considerab e difficulty in the employment thereof in the bridge frame members. dirt fills, side rails, etc., often lie so close to the rail which is to receive'the bond that only a relatively short distance is available in which the welding mechanism may be placed.

It is an object of my invention to provide an apparatus for welding bonds on rails and the like, which apparatus shall be capable of being employed in a space which is relatively narrow between the rail which is to receive the bond and any obstruction which may occur adjacent such rail.

The heat energy available at the heat distributing plate directly proportional to the electrical resistance across the arc gap; this gap is not perpendicular to the dis tributing plate but the arc thread is the revolving element of a Hat cone with the apex at the point of the electrode. The gaseous atmosphere within the ac chamber after becoming heated loses part of its resistance and not only is the useful energy of the arc cut down but the arc travels back away from the point of the electrode and the spread or diffusion of the arc is carried beyond useful limits. Some auxiliary means of maintaining the original conditions within the arc chamber during the period of high temperature ill materially assist in the efficient operation of the welding apparatus. It is, therefore, an object of my invention to provide a means whereby the electrical resistance of the a mosphere of the are chamber can be maintained and the dillusion of the are over the heat distributing plate may be kept within bounds at all times during the welding operation.

WVith the necessary intense heat associated with the proper brazing or welding of the bond to the rail and the erosion of the surrounding part'; necessarily incidental to the introduction of a resistance maintaining medium to the region of the are, means must be provided for a ready replacement of the various parts comprising the welding apparatus so that such replacements can be made easily, quickly and without the nee ssity of entirely disassembling the apparatus. It is a further object of my invention to provide an apparatus which shall have all of the above described advantages. Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain means and one mode of carrying out the invention. such disclosed means and mode illustrating, however, but one of various ways in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a side elevation of the apparatus comprising my invention shown clamped to a common form of rail; Fig. 2 is a right-side elevation of the apparatus shown in Fig. 1; Fig. 3 is a fragmentary sectional view of the furnace bOX of the apparatus shown in l and 2; Fig. 4 is a part section part elevation of the furnace box shown in Fig. 3 taken on a plane substantially indicated by the line -il; Figs. 5 and 6 are respectively front and side elevations of an alternative form of construction of the apparatus comprising my invention; Fig. 7 is a part section part elevation of the furnace box; illustrated in Fig. 6 taken on a plane substantially indicated by the line T7; Fig. 8 is an end elevation of the furnace box as shown in Fig. 5, disasseciated from the surrounding mechanism; Fig. 9 is a diagrammatic representation showing the relative position of the various parts of the apparatus comprising my invention; and Fig. 10 illustrates diagrammatically a modification in one part of the apparatus.

Referring more specifically to the drawings and more especially to Figs. 1 and 2, the apparatus here disclosed consists of a stirrupshaped body 1 which has eontai c'; therein the furnace box 2 and which has ri idly and magnetically connected tlr 'eto the bars 3, t and 5. The bar 4: has a lltliilliOll clement 6 associated therewith which is secured thereto by means of the bolts *5 and which is idapted to threadedly engage the terminal portion 8 of the screw 9. The bar a has also united therewith, and projecting therefrom, the bracket member 10 which has a bifurcated end 11 adapted to secure the pins 12b means of which the block 13 is oscillatabl secured. The block 13 threadably engages the rod ll, which has secured thereto at its lower terminal portion the bra *ket 15, by means of the set screw 16. The bracket 15 has its lowor end 16 adapted to contact with the wearing surface of the standard form of rail. The rod 14 has oscillatably secured etc at its upper end a member l7. which is adopted to rotate in a substantially hor'. tal plane ic'ng the gnaive 19 in the pin 20 projecti iioni the rod 11. The bifurcated end 21 of the nnunbcr ll is adapted to oscillatably support the threaded block 22 on the pin 23. The threaded blocl' 22 engages the screw '21 by means of which the position of the apparatus coi trolled upon rotation of the screw by the disk-like handle 2%.

The stirrup-shaped body member 1 has a bracket 25 rigidly secured thereto. which bracket is adapted to receive the electric lead 26 from the source of electrical supply. The lead 26 is secured to the bracket 25 by the nuts 27 and 28 which maintain the lead insulated from the bracket 25 by means of the insulation material 29 and 30. The nut 28 screws the flattened terminal portion 31 of the insulated lead 32 which is spirally wound on the member 5. The lead 32, after leaving the bar 5, is arched as at 33 over the stirruplike body member 1 and thence passes to the spiral winding 34 on the bar The terminal portion 35 of the lead, after it leaves the spiral windii'igs 34 on the bar 3, passes, at 36. to the upper portion of the bar 4 where it is formed into a plurality of spiral windings 37. 38 and 39, which are interconnected by 1110:1115 of the portions 49 and 41, these portions being so adapted as not to interfere with the screw 9 and the bracket 19 by which the bar 4 is supported. The terminal portion 42 of the above described lead is secured to the bracket 43 by means of the bolt 44, which bracket is in turn secured to the furnace box 2 by means of the bolt 45.

It will be seen that the bars 3, 4 and 5, which are magnetically connected to the stirrup-fori'ned body member 1, are, by means of the leads wound thereon, transformed into electric magnets. The welding current which passes through thcsc leads is therefore utilized to effect a control of the arc in the manner hereinafter more fully explained.

The terminal portion of the bar 4 is bifurcated as at 46 and adapted to secure the pin 47, which in turn secures the brace 48 which is fastened to the opposite rail of the tracks. The furnace box is caused to bear against the terminal portion 49 of the rail bond which is to be Welded to the rail 50. The rail 50 has here shown associated therewith the plates 51 and 52, by means of which adjacent rails are connected. The proper pressure of the apparatus on the bond portion 49 C()I1 trolled by means of the screw 9 and as the bond is heated the rotation of the entire apparatus in a horizontal plane through the members 18, 19 and 20 as hereinbefore described, permits the apparatus to adjust it self with respect to inclinations in the surface of the bond portion 49, either before such portion becomes heated or after heating when the surface thereof may become tapered.

The furnace box 2, most clearly shown in Fig. 3, is secured to the foot rest portion of the stirrup frame 1 by means of the bolts 55 and 56, which respectively pass through apertures formed therefor in the laterally extending flanges 57 and 58. The furnace box proper is substantially rectangular in form and consists of a main body 59, which has inwardly directed flanges 69 and 61 formed integrally therewith, which flanges support the central members 62 and 63. The body member 59 is adapted to receiy'e a block 64, preferably of some refractory material such as graphite, which block is secured in the urnace box by means of the securing frame 65, which has integrally formed there 'ith lugs 66 and 67 adapted to receive the bolts 68and 69, by means of which the frame member and the body member 59 are united.

The frame supporting member 65 has a substantially elliptical aperture 70 formed centrally thereof in its forward end, which aperture adapted to receive the rectangular flange 71 which is formed a skirt around the heat distributing plate 72. The skirt 71 contacts only at its corners with the elliptical aperture 70 and the spaces between such skirt and the frame supporting member 65 is filled with a suitable plastic cement 73, such as fire clay and the like, which secures the heat distributing plate 72 with respect to the metallic body of the furnace box and likewise furnishes a suitable heat insulating means for protecting the metallic portion of the furnace.

The block 64 has fluid wells 74 and 75 formed therein, which wells extend substan tially vertically in the normal position of the apparatus and which have fluid ducts 76 and 77, respectively leading therefrom to the substantially closed chamber 78 formed by the heat distributing plate 72, its supporting skirt 71 and the inwardly directed flange 79 of the block 64. The fluid wells 74 and 75, as most clearly shown in Fig. 2, have positioned thereon the tubular members 80 and 81, respectively, which tubular elements are in turn supported by the cylindrical projections 82 and 83 rigidly secured to the body member 59. The tubular elements 80 and 81 pass through apertures 84 and 85, respectively formed therefor in the upper portion of the stirrup-formed shell 1, and have their terminal portions formed into flared ends 86 and 87, respectively.

The body member 59 supports the insulated plate 88, most clearly shown in Figs. 1 and 3, which plate is secured by the bolts 89 and the nuts 90. The plate 88 is separated from the nuts 90 and the bolts 69 by means of the insulating material 91. The plate 88 is centrally adapted to support the tubular member 92 which in turn supports the electrode holder 93. The electrode holder 93. which frictionally secures the electrode 94 has a helical groove 95 formed in the periphery thereof, which groove coacts with the pin 96 carried by the rigidly mounted tubular member 92 so that upon rotation of the electrode holder the electrode moved axially in a direction depending upon the rotation of the holder. The electrode holder 93 has secured to its terminal portion a sheath of insulating material 97 and the circumferential flange 98 which permits such holder to be actuated by the hand of the operator.

The alternative form of the construction of the apparatus comprising my inventi on, as illustrated in Figs. 5 to 8, inclusive. is in general identical with the construction just described. For the parts in th s construction which correspond to the parts in the construction just described like reference ordinals will therefore be applied to simplify the description. Only so much of this alternative form of construction as is different from the construction just described will be further dealt with.

The means by which the entire mechanism is supported on the rails is similar to that just described, attention, however, being directed to the form of the bracket 15 which, as shown in Fig. 6, is formed with a greater length on the side normally occupied by the operator of the mechanism to permit the operator easier access to the bond which is to be welded to the rail. The general arrangement of the substantially radially extending bars 3, 4 and 5 is the same in both constructions and the arrangement of the electrical conduit thereon is identical with the cXception of the terminal portion 42, which is in this term of construction shown attached to the body of the furnace in a somewhat diilereut manner.

The stirrup-shaped body frame is of the same form as that before described, but tiu' construction of the furnace boy containen therein is different to the extent requiring a separate detail description. fire supporting body 101 of the furnace box is sibstai tially elliptical in cross-section and is as by welding or like means as at 102 to the substantially llat base 103. The base 11323 is removably secured to the foot plate if .he stirrup frame 1 by means of the bolts 01. The elliptical body 101 of the furnace box, as

most clearly shown in Fig. 7, has a similarly formed block 104, prefcrabl -r of refractory material, secured therein, which block is sup ported by a hexagonal metallic member 103 which is welded or otherwise rigidly i-ecused to the elliptical body 101 at the corners 106. The hexagonal member 105 and the blot k 104 have apertures 107 and 105%, respectively formed therein adapted in receive the elcctrode 109. Positioned on the block l" l is the heat distributing plate 72 which is supperted by the dependin skirt '51 and which facts with the elliptical body 101 only at the corners 110. The intervening space he? ween the kirt 71 and the elliptical body 101 is iilleil r l a plastic cement 73, such as fire clay. when serves as a heat insulating means between the heat distributing plate T2 and the mrtallic body 101.

The stirrupfirined body 1 has rigidly supported therein the tubular supporting means 111 which electrically iii-minted from the stirrup body by means of the insulating material 112 and is secured thereto by means of the bolt 1 13. The tube member 111 centrally adapted to receiu tion of th toothed member 113, which rigidly secured thereto the depending arm 114. The depending arm 114 is integrally united with the electrode holder to revolubly support th terminal portion 117 of the adjusting handle 118. The cylindrical portion 117 has rigidly mounted thereon the 118 which intermeshes with the toothed portion 119 of the member 113. By rotating the handle 118 the member 113 can be caused to slide in and out of the tubular member 111, and axial adjustment of the electrode 109 with respect to the heat distributing plate 7 2 is in this manner effected.

The block 104 has iiuid wells 74 and 75 lei-med therein, which have leading therefrom the ducts "It; and T7 in the manner herein he tore explained in connection with the first described construction. The tubular memat) and 81 are in Fig. 6 shown adapted cups 120 and 121, by means of which i e go erai operation of this alternative form '1' construction is the same as that of the irst term (1 int :ribed, and the operation of the described apparatus will now be briefly is a diagrammatic plan View of the in which the various parts are (invention-a1 representations in order to r.- arly show the general structure of the entir apparatus. The arms 3, 4 and 5, which connected to the stirrup-formed bad 1 are here shown to be so placed as to i the apparatus to be placed in a relail pace adjacent the rail to which the hem. is to be welded. The heat distributing plat T2 and the frame supporting member as ("which might be the electrical membrr 101) are shown diagrammatically projes from the bony 1 of the apparatus and, so e ecting, directed against the bond termin he apparatus is positimied on the rail as shown in his. 1, the bend terminal 49 proprpositioned with respect to the rail 50 and heat distributing plate 72 and the entire apparatus then rigidly secured in place by ans oi the brace lo and the proper preswed by means of the screw 9. The I is then connected to a suitable source of electric current and the electrod 94 moved forward toward the heat distributing plate until electrical contact is established, hereupon current will llow through the entire circuit. lly means of the electrode hold- -r at; or 115 the electrode is then retracted ironi th plate 72 and the arc struck. A suitable fluid such as water, is then introduced to fluid wells F4 and 1'5, either by means of sight cups; as illustrated in Figs. 5 and 6 or through the flared ends 86 and 87 as shown in F3 :2, which fluid, when the block 64 or 111- uliicicntly heated, will pass through ll e ducts T6 and 17 provided therefor into the si bstantially closed chamber 78. The effect of he welding current passing through the leads wound on the rods 3, 4 and 5 is to set up a magnetic field which causes the arc to iiYci be spread over the ma face of the heat distributing plate 72. This spreading of the arc by the magnetic field is assisted by the vapor ejected by the ducts 76 and 77. and a further effect of the vapor leaving these ducts is to maintain the effect of the are against the inner surface of the heat distributing plate.

Instead of utilizing the simple wells 74 and 75 with flared or funnel ends 86 and 87 (Fig. 2), or the tubes 80 and 81 with feed cups 120 and 121 (Fl 6) through which to introduce water or equivalent fluid into the closed chamber 78, I may employ automatic, preferably magnetically controlled, water supply means such as shown for example in Fig. 10. Such magnetic control depends upon the observed fact that the introduction of water into the chamber 78 increases the voltage across the are and that the heating may be held at a high intensity by adding additional water as such voltage drops to any predetermined "alue. Accordingly, in the device illustrated in Fig. 10, water reservoirs 125 and 126 take the place of the flared or funnel ends on the wells 80 and 81 of the apparatus illustrated in Figs. 1 and 2 or the equivalent tubes 80 and 8! of the modified form of the apparatus illustrated in Figs. 5 and 6. The escape of the water in said reservoirs is normally prevented by needle valves 127 and 128 which are held to their seats by springs 129 and 130, respectively. Associated with the respective stems of such valves are solenoids 131 and 132 which when energized are adapted to withdraw the valves from their seats, the amount of such withdrawal being regulated by adjustable stops 133 and 134.

In addition to valves 127 and 128 just described, plug valves or stop cocks 135 and 136 are provided in the wells or tubes below the reservoirs 125 and 126, respectively, such last mentioned valves being arranged for conjoint operation by means of a third solenoid 137, the core 138 of which is operatively connected with said valves as shown. All three solenoids are connected in series in a shunt circuit from points A and B on the welder and rail being welded, respectively, the arrangement being such that as needle valves 127 and 128 open, the valves 135 and 136 close with the closing of the circuit; however, as the voltage across points A and B of the apparatus begins drop, the valves open in proportion to the drop and allow water to flow accordingly. Adjustments of solenoid action are made by varying the stops 133 and 134- as well by varying the tension of the several springs employed in connection with the valves and by selecting proper windings for the solenoids themselves, all as will be readily understood.

The vapor upon entering the region of the arc renews the atmosphere of the chamher in such manner as to maintain the elecor portion of the innertrical resistance and to limit the spread of the are on the heat distributing plate 72 as well as to blow the are forward against the heat distributing plate.

The construction and arrangement of the various parts as illustrated in Fig. 3 permits of a ready disassembly of the furnace box and a quick replacement of parts which is particularly advantageous when repairs are to be made in the field, as is usually the case.

The arrangement of parts 3, 4 and 5, which with the stirrup-formed shell with which they are magnetically connected, establishes substantially the same resulting electromagnetic field around the electrode and the same distribution of the are over the inner surface of the heat distributing plate 72 is effected as when a solenoid, co-axially mounted with such electrode, is employed. The advantage of this type of construction is that there are no parts which project for a substantial distance at right angles to the rail which would be interfered with by guard rails, embankments and the like. The apparatus and the method herein disclosed accomplish a distribution of the are over the surface of the heat distributing plate as well as an augmentation of the heat supplied by the electric arc in a manner not possible with any of the apparatus or methods now in use.

7 Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the process herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

I therefore particularly point out and directly claim as my invention 1. In apparatus of the character described, the combination of a heat distributing plate adapted to contact with the surface to be heated; means for directing an are against said plate; and means for spreading such are over the surface of said plate, said means including an electro-magnetic coil disposed with its axis substantially normal to such arc; and a core for said coil.

2. In apparatus of the character described, the combination of a heat distributing plate adapted to contact with the surface to be heated; means for directing an are against said plate; and means for spreading such are over the surface of said plate, said means including plural spaced electro-magnetic coils extending substantially radially from said are; and cores for said coils.

3. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated; means for directing an are against said plate; and means for spreading such are over the surface of said plate, said means including a metallic shell disposed with its axis in substantial ali nment with such arc, an electro-magnetic coil disposed with its axis substantially normal with such arc; and core for said coil in magnetic contact with said shell.

4. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated, means for directing an are against said plate; and means for spreading such are over the surface of said plate, said means including a metallic sh ll disposed with its axis in :-:1ibstantial alignment with such arc; plural spaced electro-magnetic coils extending substantially radially from said arc; and cores for said coils in magnetic contact with said shell.

5. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated; means for directing an arc against said plate; and means for spreading such are over the surface of said plate, said means including means for supplying a directed stream of fluid to such arc.

6. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated, said plate form ng one side of a substantially closed chamber, means for directing an arc in said cnamber against said plate, means for spreading such are over the surface of said plate, and means for supplying vapor to said chamber.

7. In apparatus of the character described, the combination of a. neat-distributing plate adapted to Contact with the surface to be heated, said plate forming one side of a substantially closed chamber, means for directing an arc against said plate; means for spreading such are over the surface of said plate, and means for supplying a directed stream of fluid into said chamber to such arc.

8. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated. said plate forming one side of a substantially closed chamber, means for directing an are against said plate; means for spreading such are over the surface of said plate; and means for supplying a directed st ream of Vapor to such are in said chamber.

9. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated, said plate forming one side of a substantially closed chamber, means for directing an are against said plate; means for spreading such are over the surface of said plate; and means for supplying a stream of fluid to such chamber in substantial alignment with and directed toward the axis of said arc.

10. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated; said plate forming one side of a substantially closed chamber, means for directing an are against said plate; means for spreading such are over the surface of said plate; and means for supplying a pinrality of circumferentially spaced streams of fluid to such chamber in subslantial alignment with and directed toward the axis of said are.

11. In apparatus of the character described, the combination of a heat distribut ing plate adapted to contact with the surface to be heated; means for directing an are against said plate; means for spreading such are over the surface of said plate, said means including an electro-magnefic coil disposed with its axis substantially normal to such are: a core for said coil; and means for supplying directed streams of fluid to such are at acute angles to the axis thereof.

12. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with th surface to be heated; means for directing an are against said plate; means for spreading such are over the surface of said plate, said means including a plurality of elctro-magnetic coils arranged with their axes extending radially from the axis of the arc; cores for said coils; and means for supplying a directed stream of fluid to such are.

13. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated; means for directing an are against said plate; means for spreading such are over the surface of said plate, said means including a metallic shell dispo ed with its axis in substantial alignment with such are; an electro-n'iagnetic coil disposed with i s axis substantially normal with such are; a core for said coil in magnetic contact with said shell; and means for supplying a directed stream of fluid to such arc.

14. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to V be heated: means for directing an are against said plate; means for spreading such are over the surface of said plate, said means including a metallic shell disposed with its axis in substantial alignment with such arc; a plurality of spaced electro-n:agnetic coils disposed with their axes substantially normal to the axis of such are; cores for said coils in magnetic contact with said shell; and means for supplying a directed stream of fluid to such arc.

15. In apparatus of the chufactcr dc scribed, the combination of a heat-distributing plate adapted to contact with the surface to be heated; means cooperating with said plate to form a substantially closed chamber, means for directing an are against said plate;

and means for supplying a resistance maintaining medium to such are.

16. In an apparatus of the character described, the combination of a heat-distributing plate adapted to contact 'ith the surface to be heated; means cooperating with said plate to form a substantially closed chamber, means for directing an are against. said plate; means for spreading such are over the surface of said plate; and means for supplying a resistance maintaining medium to sum arc.

17. In an apparatus of th character described, the combination of a healdistributing plate adapted to contact with the surface to be heated; means cooperating with s id plate to form a substantially closed chamber, means for directing an arc against said plate; and means for supplying a fluid to such arc to augment and ontrol the tempcrmure imparted to said plate.

18. In an apparatus of the character described, the combination of a hcat-distribut' ing plate adapted to contact with the surface to be heated; means for directing an are against said plate; a s1ibstantiall closed chamber for confining such ar and means for supplying a fluid to such chamhcr.

19. In an apparatus of the clu-u'a-at r described, the combination of a ll(at-dl liib!!iing plate adapted to contact with the surface to be heated; means for directing an against said plate; a sub tauti: lly clos d chamber for confining such arc: and meat for maintaining the e ectrical resistance of such arc, said means including meow plying fluid to said chamber.

20. In apparatus of the charm-tor described, the combimitiou of a heat-distributing plate adapted to contact with the surface to be heated, an aiially :l 'u:'-:tab" V for directing an a a air fractory means surreum in; form with F illtl plate a. sub; chan'iber, means for suppcrti. and said refractory meaas. an effecting axial adjustment of including a supporting sleeve, holder for said electrode, and a pin on one of said last named members engaging a helical groore on the other of said members.

521. In apparatus of the character described, the combination of a heat-distrilrst-- ing plate adapted to contact with the surface to be heated, an axially adjustable elcctr-ode for directing an are against said plate. fraetory means surrounding said electr e form with said plate a substantie-J chan'iber, means for supporting and said refractory means elcctrica lated means secured to said l 1 means for .n p 'iorting said elcctro means associateal with said insulated for axially adjusting said electrode.

22. In apparatus of the character described, the combination of a heat-distribut- -cr suni; clog-cil said gilt-"e means or electr: a in upp ing plate adapted to contact with the surface to be heated, an axially adjustable electrode for directing an are against said plate, refractory means surrounding said electrode to form with said plate a substantially closed chamber, fluid wells in said refractory means, fluid ducts from said wells to said chamber, means for supporting said plate and said refractory means, and means for effecting axial adjustment of said electrode.

23. In apparatus of the character described, the combination of a heat-distributing plate adapted to contact with the surface to be heated, an axially adjustable electrode for directing an arc against said plate, refractory means surrounding said electrode to form with said plate a substantially closed chamber, means for supporting said plate and said refractory means, means for suppor ing said electrode, an electrode holder, helical grooves in said holder, and means associated with said electrode supporting means adapted to coact with said helical groove to effect axial adjustment of said electrode.

24.1:1 apparatus of the character de-' and said refractory means, a body member adapted to receive said refractory means and removably secure said metallic supporting means, an electrode for directing an arc a ainst said plate, and means associated with s id body member for supporting and effecting axial adjustment of said electrode.

3. In a iethod of uniting contacting metal bodies, the steps which consist in pressing a lieat-distributing shield against the exposed face of one of such bodies, directing an arc ,Q ainst the face of such shield opposite to hat face in contact with such metal body, and uiroducing a stream of fluid to such are to limit the spread of the same over the major portion of such shield.

26. In a method of uniting contacting metat lUOtllPb, the steps which consist in pressing a heat-d stributing shield a 'a nst the exposed face of one of such bodies. directing a laterally contined are against the face of such shichl opposite to that face in contact with such i'nctal body, and supplying a resistance increasing fluid to such arc.

[n a method of uniting contacting metal bodies. the steps which consist in pressing 28. In a method of uniting contacting metal bodies, the steps which consist in pressing a heat-distributing plate against the exposed face of one of such bodies, directing an are against the face of such plate opposite to that face in contact with such metal body,

and introducing a plurality of directed diametri ally opposed streams of fluid to such are to spread the same over the major portion of said plate and to maintain constant the resistance of such are.

10 29. In a method of homogeneously uniting a copper bond to a rail, the steps Which consist in placing a heat-distributing plate against the exposed face of the bond terminal, directing an are against the face of said plate opposite to that face in contact With such metal body. and introducing a plurality of directed diametrically opposed streams of fluid to such are to spread the same over the major portion of said plate and to maintain constant the resistance of such arc.

30. In a method of homogeneously uniting a copper bond to a rail, the steps which consist in placing a heat-distributing plate against the exposed face of the bronze sheathed bond terminal, directing an are against the face of said plate opposite to that face in contact with such metal body, and introducing a stream of fluid to such arc to spread the same over the major portion of such shield and to maintain constantthe resistance of such arc.

31. In apparatus of the character described, a substantially closed chamber, heat-distributing plate forming one Wall of said chamber and adapted to contact With the surface to be heated, means for directing an arc in said chamber against said plate, and means for introducing Water into said chamber to increase the heating effect of the arc.

In apparatus of the character described, a substantially closed chamber, a heat-distributing plate forming one wall of said chamber and adapted to contact with the surface to be heated, means for directing an arc in said chamber against said plate, and means for supplying Water-vapor to said chamber.

Signed by me, this 2nd day of January, 1930. CHARLES A. CADYVELL. 

